A Critical Appraisal of Gluten in Skin Disorders, the Evidence So Far, and Updated Recommendations.

Gluten, a polypeptide hapten, found in many cereals such as barley, wheat, rye, oats, and others, has been recently implicated in a range of cutaneous disorders ranging from chronic plaque psoriasis through psoriatic arthritis, urticaria (chronic as well as paediatric onset), and angioedema to lichen planus, vitiligo, and rosacea. The evidence for them is still not well reviewed. To generate evidence for the causal role of gluten in various dermatological disorders. The Pubmed, MedLine, and EMBASE databases were searched using the keywords "Gluten" and one of the dermatoses, namely, "Atopic Dermatitis", "Vasculitis", "Psoriasis", "Psoriatic Arthritis", "Acne", "Alopecia Areata", and "Immunobullous disorders". All articles published in English for which free full text was available were taken into consideration. The search strategy returned in a total of 1487 articles which were screened for relevance and elimination of duplicates. Ultimately, around 114 articles were deemed suitable. The data were extracted and presented in the narrative review format. A simple and cost-effective solution to many of these chronic and lifelong conditions is to restrict gluten in the diet. However, the dermatologist would do well to remember that in the vast majority of dermatological disorders including the ones listed here, gluten restriction is not warranted and can even lead to nutritional deficiencies. The evidence varied from Grade I for some disorders like psoriatic arthritis to Grade IV to most disorders like acne, vitiligo, vasculitis, and atopic dermatitis. Herein, we review the evidence for each of these conditions and make practical recommendations for gluten restriction in them.